have you got an uprated intercooler james ? If you have why not turn the boost up a bit, you should get 220bhp then with those mods !

What about a gas flowed head ? When I ran my car at 11psi it was pants, only about 170 bhp but when the boost was turned up I saw 257bhp !! If you get an uprated head you will see loads more power for the boost, especially if you have the other mods to go with it like you have ! something to think about at least